PROJECT SUMMARY. The goal of this CEBRA is to integrate cutting-edge concepts from nanotechnology, immunology, and addiction to develop nanovaccines to treat heroin and prescription opioid abuse and prevent fatal overdose. Opioid abuse is a major national emergency in the US with an enormous cost in human tragedy as well as health care costs. Abuse of heroin and prescription drugs such as oxycodone is increasing annually, and everyday more than 90 people die of opioid overdose. While medications to treat opioid addiction are available, their use is limited from side effects, tight prescription guidelines, and restricted availability. We expected that development of immunotherapies to treat addiction will provide safe and cost-effective alternatives to opioid-based medications. Vaccines elicit opioid-specific antibodies that sequester opioids in the periphery, limit free (unbound) opioid distribution to the brain, and prevent opioid-induced behavior and toxicity. In the clinic, addiction vaccines have the potential to augment existing pharmacotherapies, and prevent fatal overdose upon relapse in abstinent users. We propose the use of rationally designed peptide amphiphiles (PAs) as carriers for oxycodone and heroin haptens and investigate vaccine efficacy in pre-clinical models. We propose two aims: Aim 1) Test the efficacy of opioid vaccines containing PA nanocarriers to induce opioid-specific antibodies that block heroin and oxycodone distribution to the brain and Aim 2) Generate multivalent PA-based nanovaccines that target both heroin and oxycodone and test vaccine efficacy in pre- clinical models of opioid abuse. Our approach will be to synthesize and characterize PAs conjugated to oxycodone and heroin haptens and investigate the effect of nanocarrier morphology and charge on the quantity and quality of the opioid-specific antibody response in immunized mice. We will also test the role of T cell helper epitopes and exogenous adjuvants in improving antibody titers and affinity in combination with PA nanocarriers. Further, we will develop bivalent vaccines composed of oxycodone PAs and heroin PAs and test their efficacy to block opioid distribution to the brain of immunized mice challenged with single or cumulative opioid dosing. Promising formulations will be tested in mouse models of opioid-evoked antinociception, motor activity and respiratory depression and also confirmed in an outbred mouse strain. Successful completion of these studies will generate novel nanomaterials-based opioid vaccines and provide a framework for the development of vaccines against other drugs of abuse.